In the real-time and embedded domain, systems tend to combine periodic and aperiodic computations. This leads to mixing event-triggered with timetriggered communications with their pros and cons. Then, modeling standards of the domain must provide mechanisms to support both kinds whereas historically they pertain to different communities: asynchronous and synchronous designers. In this paper, we compare the expressiveness of two standards of the domain (AADL and MARTE) to model these two kinds of communications. Specifically we focus on the Time facilities of MARTE and on AADL models amenable to end-to-end flow latency analyses.